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RESEARCH PRODUCT
Microscopic observations of superficial ultrastructure of unworn siloxane-hydrogel contact lenses by cryo-scanning electron microscopy
Miguel F. RefojoAntonio López-alemanyManuel A. ParafitaJosé B. AlmeidaJosé Manuel González-méijomesubject
Materials scienceSiloxanesScanning electron microscopeSurface PropertiesBiomedical Engineering02 engineering and technologyContact lens materialsHydrogel Polyethylene Glycol Dimethacrylatelaw.inventionBiomaterials03 medical and health sciences0302 clinical medicineOpticssilicone-hydrogellawMicroscopyMaterials TestingHumansCryo-scanning electron microscopyComposite materialchemistry.chemical_classificationScience & Technologybusiness.industryCryoelectron MicroscopyCryoSEM microscopyPolymerLiquid nitrogenpolymer surface021001 nanoscience & nanotechnologyContact Lenses HydrophilicSiloxane-hydrogel contact lensescryoSEMLens (optics)Contact lenschemistry030221 ophthalmology & optometryUltrastructuremicroscopysiloxane-hydrogels0210 nano-technologybusinessdescription
The purpose of this study was to analyze three commercial siloxane-hydrogel contact lens materials, lotrafilcon A, balafilcon A, and galyfilcon A, by cryogenic scanning electron microscopy (cryoSEM). The fully hydrated lenses were frozen in slush liquid nitrogen and qualitatively observed in a cryogenic scanning electron microscope. The superficial ultrastructure of the siloxane-hydrogels was observed at the areas where the lens fractured during sample cryogenic preparation. There are qualitative differences among the three examined materials in the complex polymer network structure existing between the outer layer and the underlying polymer. CryoSEM, although destructive, is a useful tool to investigate the structure of polymers used in contact lenses. This technique allows the observation of the inner structure of polymers in the hydrated state. The ultrastructure, the polymer network underlying the outer surface of siloxane-hydrogels by cryoSEM microscopy, have never been reported before.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2006-02-01 |